134 LIFE AND DEATH. 



With Gotte, the conception of reproduction, like the conception of 

 death, is a protean form, which he welcomes in any shape, if only 

 he can use it as evidence. If death is a necessary consequence of 

 reproduction, its cause must be always essentially the same, and 

 might be expressed in one of the following suggestions: (i) in 

 the necessity for a 're-coining' of the protoplasm of the germ- 

 cells ; but here death could only affect the germ-cells themselves : 

 (2) perhaps in the withdrawal of nourishment by the mass of 

 developing reproductive material, just as death occurs sometimes 

 among men by the excessive drain on the system caused by morbid 

 tumours : (3) or in consequence of the development of the off- 

 spring in the body of the mother ; this however would only affect 

 the females, and could therefore have no deep and general signifi- 

 cance : (4) from the extrusion of the sexual cells, ova or sper- 

 matozoa, and in the impossibility of further nourishment which is 

 consequent upon this extrusion (Orthonectides ?) : or (5) finally in 

 an excessively powerful nervous shock brought about by the ejection 

 of the reproductive cells. 



But no one of these alternatives is the universal and inevitable 

 cause of death. This proves irrefutably that death does not proceed 

 as an intrinsic necessity from reproduction, although it may be 

 connected with the latter, sometimes in one way and sometimes 

 in another. But we must not overlook the fact that in many 

 cases death is not connected with reproduction at all ; for many 

 Metazoa survive for a longer or shorter period after the repro- 

 ductive processes have ceased. 



In fact, I believe I have definitely shown that no process exists 

 among unicellular animals which is at all comparable with the 

 natural death of the higher organisms. Natural death first ap- 

 peared among multicellular beings, and among these first in the 

 Heteroplastids. Furthermore, it was not introduced from any 

 absolute intrinsic necessity inherent in the nature of living matter, 

 but on grounds of utility, that is from necessities which sprang 

 tip, not from the general conditions of life, but from those special 

 conditions which dominate the life of multicellular organisms. 

 If this were not so, unicellular beings must also have been en- 

 dowed with natural death. I have already expressed these ideas 

 elsewhere 1 , and have briefly indicated how far, in my opinion, 



1 See the first essay upon ' The Duration of Life,' p. 22 et seq. 



